U.S. patent application number 10/305235 was filed with the patent office on 2003-07-03 for control circuit for vehicular power transmission apparatus, and abnormality determining device for the control circuit.
Invention is credited to Kumazawa, Atsushi, Nakamura, Takeshi, Ogi, Osamu, Umemoto, Osamu.
Application Number | 20030125861 10/305235 |
Document ID | / |
Family ID | 19173636 |
Filed Date | 2003-07-03 |
United States Patent
Application |
20030125861 |
Kind Code |
A1 |
Nakamura, Takeshi ; et
al. |
July 3, 2003 |
Control circuit for vehicular power transmission apparatus, and
abnormality determining device for the control circuit
Abstract
An interruption circuit capable of interrupting an electrical
power fed from a power source unit to a driver circuit in response
to an interruption signal from an electronic control unit is
interposed between the driver circuit for activating power
transmission means and the power source unit. By this arrangement,
it is possible to interrupt the electrical power fed from the power
source unit to the driver circuit forcibly and prevent unnecessary
power consumption and unnecessary action (or a malfunction) of the
power transmission means.
Inventors: |
Nakamura, Takeshi; (Tokyo,
JP) ; Kumazawa, Atsushi; (Kanagawa, JP) ; Ogi,
Osamu; (Kanagawa, JP) ; Umemoto, Osamu;
(Kanagawa, JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
19173636 |
Appl. No.: |
10/305235 |
Filed: |
November 27, 2002 |
Current U.S.
Class: |
701/63 |
Current CPC
Class: |
F16H 2061/1292 20130101;
F16H 61/12 20130101; F16H 2061/1224 20130101; F16H 2061/005
20130101 |
Class at
Publication: |
701/63 |
International
Class: |
G06F 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 28, 2001 |
JP |
2001-363262 |
Claims
1. A control circuit abnormality determining device for a vehicular
power transmission apparatus, comprising: power transmission means
for transmitting a driving force of an engine to an output member;
an actuator for switching operations of said power transmission
means; a driver circuit for driving said actuator; a power source
unit for generating an electric power; a power supply circuit for
supplying the electric power to said driver circuit; interruption
means for selectively interrupting the electrical power fed from
said power source unit to said driver circuit; a control unit for
outputting a drive signal to said driver circuit and an
interruption signal to said interruption means; and abnormality
determining means for determining an abnormality of the electrical
power fed to said driver circuit on the basis of presence and
absence of the output of said interruption signal and presence and
absence of the electrical power fed to said driver circuit.
2. A control circuit abnormality determining device of a vehicular
power transmission apparatus according to claim 1, wherein said
abnormality determining means determines that the electrical power
fed to said driver circuit is abnormal, when said interruption
signal is outputted and the electrical power is fed to said driver
circuit, or when said interruption signal is not outputted and the
electrical power is not fed to said driver circuit.
3. A control circuit abnormality determining device of a vehicular
power transmission apparatus according to claim 1, further
comprising: a preparatory circuit of said power supply circuit for
supplying the electrical power from said power source unit to said
driver circuit, wherein said preparatory circuit is used when said
abnormality determining means determines the abnormality in an
electrical power supply based on absence of the interruption signal
and absence of electrical power fed to said driver circuit.
4. A control circuit abnormality determining device of a vehicular
power transmission apparatus according to claim 1, wherein said
actuator is a gear-shift unit for an automatic transmission.
5. A control circuit abnormality determining device of a vehicular
power transmission apparatus according to claim 1, wherein said
actuator is a friction clutch actuator interposed between the
engine and the output member.
6. A control circuit abnormality determining device of a vehicular
power transmission apparatus according to claim 1, wherein said
control unit outputs said interruption signal when an engine key
switch is OFF.
7. A control circuit structure of a vehicular power transmission
apparatus, comprising: power transmission means for transmitting
the driving force of an engine to an output member; an actuator for
switching operations of said power transmission means; a driver
circuit for driving said actuator; a power source unit for feeding
an electrical power to said driver circuit; interruption means for
interrupting the electrical power fed from said power source unit
to said driver circuit selectively; and a control unit for
outputting a drive signal to said driver circuit and an
interruption signal to said interruption means.
8. A control circuit abnormality determining device for a vehicular
power transmission apparatus, comprising: a driver circuit that
drives an actuator that switches operations of a power transmission
unit; an interruption unit that selectively interrupts an
electrical power supplied to said driver circuit; a control unit
that outputs a drive signal to said driver circuit and an
interruption signal to said interruption unit; and an abnormality
determining unit that determines an abnormality of the electrical
power supplied to said driver circuit based on presence and absence
of said interruption signal and presence and absence of the
electrical power supplied to said driver circuit.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This non-provisional application claims priority under 35
U.S.C. .sctn.109(a) on patent application No. 2001-363262 filed in
Japan on Nov. 28, 2001, which is herein incorporated by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a control circuit for
controlling a gear-shift unit for shifting a mechanical-type
automatic transmission or a clutch control unit for
applying/releasing a clutch interposed between an engine and the
mechanical-type automatic transmission, and also to an abnormality
determining device for the control circuit.
[0004] 2. Description of the Related Art
[0005] As a transmission for an automobile, there has been a
mechanical-type automatic transmission, which is provided with a
speed-changing gear mechanism and a clutch mechanism similar to
those of a manual automobile, an actuator (or a gear-shift unit)
for driving the speed-changing gear mechanism and an actuator (or a
clutch control unit) for driving the clutch mechanism, and an
electronic control unit (ECU) for controlling those individual
actuators. This mechanical-type automatic transmission has been
centrally applied to a large-sized vehicle such as a truck or a
bus.
[0006] Here, in a vehicle having an air pump, the gear-shift unit
can be constructed with actuators using pneumatic pressure. In a
vehicle having no air pump, however, it is more advantageous in
terms of the mounting space and cost by utili1zing electric
actuators rather than providing a new air pump.
[0007] In the case of the clutch control unit, it is also more
advantageous to utilize electric actuators which in combination
with an electric pump for producing a fluid pressure or an electric
motor.
[0008] In the case of the mechanical-type automatic transmission
having such electric actuators, a structure, as shown in FIG. 7,
can be generally considered. More specifically, as shown in FIG. 7,
a driver circuit 33 for controlling the actions of a gear-shift
unit 31 and a driver circuit 23 for controlling the actions of a
clutch control unit 21 are integrated, and that the driver circuits
33 and 23 are connected via signal lines 81 and 82 with an ECU 41
for controlling those actuators 31 and 21.
[0009] On the other hand, the electric current for driving the
gear-shift unit 31 or the clutch control unit 21 has to be fed from
a battery 70 through the driver circuits 33 and 23 to the
gear-shift unit 31 or the clutch control unit 21. It is, therefore,
necessary to provide a power feeding harness (or a power feed line)
73 from the battery 70 on the chassis side to the driver circuits
33 and 23 to provide power feeding harnesses (or power feed lines)
74 and 75 from the driver circuits 33 and 23 to the gear-shift unit
31 and the clutch control unit 21 on the chassis side.
[0010] The driver circuits 33 and 23 are arranged apart from the
ECU 41, as described above, for the following reasons.
[0011] The actuators, such as the gear-shift unit 31 and the clutch
control unit 21, are disposed in the vicinity of an engine, which
has a high temperature and a serious vibration. This is not a
suitable environment for the ECU 41. Therefore, the ECU 41 is
arranged apart from the gear-shift unit 31 and the clutch control
unit 21.
[0012] Moreover, the actuators, such as the gear-shift unit 31 and
the clutch control unit 21, have to be fed with a large current so
that a large capacity electric wires for the large current have to
be used as the harnesses 73, 74, and 75. To suppress increase in
cost and weight, therefore, it is effective to reduce the lengths
of the harnesses 73, 74, and 75. The lengths of these harnesses 73,
74, and 75 can be reduced, if the driver circuits 33 and 23 are
arranged apart from the ECU 41 and close to the gear-shift unit 31,
the clutch control unit 21, and the battery 70.
[0013] However, in a system where an electric actuator utilizing
the electric motor or the like, or a solenoid valve is adopted in
the gear-shift unit or the clutch control unit, the following
problems occur if the driver circuits 33 and 23 for driving the
electric motor or the solenoid valve are separated from the ECU 41
and arranged near the battery 70 so that the drive power may be
taken directly from the battery.
[0014] In case any abnormality occurs in the system, a malfunction
may be caused despite no drive signal is provided from the ECU, and
the vehicle may exhibit unexpected behaviors.
[0015] If a minute current flows in the drive signal line when the
engine key is OFF, the battery may be exhausted by the malfunction
of or the power consumption by the actuator.
SUMMARY OF THE INVENTION
[0016] The present invention contemplates to solve such problems
and has an object to provide a control circuit structure of a
mechanical-type automatic transmission, which utilizes electric
devices as a gear-shift unit and a clutch control unit and which is
enabled to prevent the malfunction of the electric devices or
unnecessary consumption of a power source by disposing an
electronic control unit at a portion of an better environment
spaced from the gear-shift unit or the clutch control unit and by
making an electric wire for a large current as short as possible to
reduce the cost and weight.
[0017] According to the present invention, there is provided a
control circuit abnormality determining device for a vehicular
power transmission apparatus, which comprises: a power transmission
unit for transmitting a driving force of an engine to an output
member; an actuator for switching actions of said power
transmission unit; a driver circuit for driving said actuator; a
power source unit for feeding an electric power to said driver
circuit; an interruption unit capable of interrupting power feed
from said power source unit to said driver circuit selectively; an
electronic control unit for outputting a drive signal to said
driver circuit and an interruption signal to said interruption
unit; and an abnormality determining unit for determining an
abnormality of the power feed to said driver circuit on the basis
of presence/absence of the output of said interruption signal and
the presence/absence of the power feed to said driver circuit.
[0018] On the basis of the presence/absence of the output of the
interruption signal to be outputted from the electronic control
unit to the interruption unit and the presence/absence of the power
feed from the power source unit to the driver circuit, it is
possible to determine the unexpected abnormality of the power feed
to the driver circuit or the abnormality of the disconnection of
the power feed circuit from the power source unit to the driver
circuit, thereby to prevent the malfunction of the actuator.
BRIEF DESCRIPTION OF DRAWINGS
[0019] FIG. 1 is a schematic construction diagram showing a control
circuit structure of a mechanical-type automatic transmission
according to a first embodiment of the present invention;
[0020] FIG. 2 is a construction diagram showing a drive system of
an automobile equipped with a mechanical-type automatic
transmission according to the individual embodiments of the
invention;
[0021] FIG. 3 is a diagram showing a gear-shift unit according to
the control circuit structure of the individual embodiments of the
invention;
[0022] FIG. 4 is a diagram showing a clutch control unit according
to the control circuit structure of the individual embodiments of
the invention;
[0023] FIG. 5 is a schematic construction diagram showing a control
circuit structure of a mechanical-type automatic transmission
according to a second embodiment of the invention;
[0024] FIG. 6 is a schematic construction diagram showing a control
circuit structure of a mechanical-type automatic transmission
according to a third embodiment of the invention; and
[0025] FIG. 7 is a schematic construction diagram showing a
conventional control circuit structure of a mechanical-type
automatic transmission.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] The embodiments of the present invention will be described
in detail with reference to the accompanying drawings.
[0027] A first embodiment of the invention will be described with
reference to the drawings.
[0028] FIG. 1 is a diagram showing a control circuit structure of a
mechanical-type automatic transmission according to the first
embodiment of the present invention; FIG. 2 is a diagram showing a
drive system of an automobile equipped with a mechanical-type
automatic transmission according to the individual embodiments of
the invention; FIG. 3 is a diagram showing a gear-shift unit
according to the control circuit structure; and FIG. 4 is a diagram
showing a clutch control unit according to the control circuit
structure.
[0029] First of all, the mechanical-type automatic transmission
according to the embodiment is attached to an engine 1 mounted on
an automobile (e.g., a truck provided with a cab on a chassis), as
shown in FIG. 2. The automobile is provided with a clutch mechanism
(as simply called "a clutch") 2 attached to the output portion of
the engine 1 and having a friction clutch, and a mechanical-type
automatic transmission body 3 connected to that clutch mechanism 2
to the output portion of the engine 1.
[0030] Moreover, the clutch mechanism 2 is selectively connected or
disconnected by a clutch control unit (or a clutch booster) 21
acting as a clutch actuator. The clutch control unit 21 is provided
with an electric pump 22 such as an electric actuator, as shown in
FIG. 4, such that the clutch mechanism 2 selectively is connected
or disconnected by feeding the not-shown master cylinder or a slave
cylinder through a control valve 21a with a fluid pressure (or oil
pressure) produced by the electric pump 22. Here, the control valve
21a is driven through a solenoid selector valve 21b. Moreover, the
oil pressure is fed from a working oil tank 21c and regulated to a
predetermined pressure by a control valve 21d.
[0031] The transmission body 3 is shifted by a gear-shift unit
(GSU) 31 acting as a gear-shifting actuator. This gear-shift unit
31 is provided, for example, with an electric motor 32a for driving
the gear-shift member in a select direction, and an electric motor
32b (both electric motors have been designated by reference numeral
32 hereinafter, although not discriminated) for driving the
gear-shift member in a shift direction, as shown in FIG. 3, such
that it is constructed as an electric actuator. At the time of a
speed change, moreover, the gear position is shifted to a desired
state by driving a desired portion with the electric motor 32 to
switch the meshing state of the gear mechanism of the transmission
body 3.
[0032] The engine 1 is controlled by drive signals from an engine
electronic control unit (or engine ECU) 42, and the clutch control
unit 21 and the gear-shift unit 31 are controlled with drive
signals from a transmission electronic control unit (or
transmission ECU) 41 or an electronic control unit for the
transmission.
[0033] Moreover, this mechanical-type automatic transmission can
select and execute a manual mode, in which a shift command of the
gear position by the manual control of the driver is sent as an
electric signal to the control circuit unit 21 and the gear-shift
unit 31 thereby to control the control circuit unit 21 and
gear-shift unit 31 remotely, and an automatic shift mode, in which
the actions of the control circuit unit 21 and the gear-shift unit
31 are controlled when the switching of the gear position is
necessary for an optimum gear speed according to the running state
(e.g., the vehicle speed or the engine load) of the vehicle.
[0034] Therefore, the transmission ECU 41 is provided with a manual
shift remote operation control unit 41a for a manual shift control
by a remote operation in a manual shift mode, and an automatic
shifting remote operation control unit 41b for an automatic shift
control in an automatic shift mode by controlling the clutch
releasing action, the gear-shift action, and the clutch applying
action.
[0035] The transmission ECU 41 is connected individually with: a
change lever unit 5 that functions as shift operation means and
manual/automatic select operation means; a vehicle speed sensor
(acting as vehicle speed detecting means) 51 for detecting the
speed of the vehicle; a clutch stroke sensor 52; a clutch switch 53
for detecting the depression of a clutch pedal 6; a transmission
gear sensor (not shown) for detecting the gear position of the
transmission body 3; a clutch speed sensor (acting as clutch output
rotation detecting means) 54 for detecting the clutch rotation
speed (i.e., the output side speed of the clutch mechanism 2); a
stop lamp switch (including the type which detects the air pressure
of a brake) 56 that is turned ON, when a brake pedal 7 is
depressed, for detecting an operation of the brake; an emergency
switch (not shown); an indicator 60; a parking brake switch 59; a
key switch 62; and so on, so that it inputs various kinds of
signals (as referred to FIG. 2).
[0036] On the other hand, the engine ECU 42 is connected
individually with the key switch 62; the vehicle speed sensor 51;
an accelerator depression sensor 57; an engine speed sensor 58; the
transmission ECU 41; an exhaust brake system 61; and so on. Here,
the accelerator depression sensor 57 is attached to an accelerator
pedal 8.
[0037] When the manual shift mode is selected through the change
lever unit 5, moreover, either only the gear-shift unit 31 or both
the gear-shift unit 31 and the clutch control unit 21 are remotely
controlled on the basis of the command from the change lever unit 5
through the manual shifting remote operation control unit 41a
disposed in the transmission ECU 41.
[0038] In short, in the manual shifting remote operation control
unit 41a, the operations for the clutch disengagement, the gear
change, and the clutch engagement are controlled in the manual
shift mode merely by operating a change lever 5a of the change
lever unit 5 to operate the gear-shift unit 31 and the clutch
control unit 21 manually while driving the essential portion of the
transmission body 3 and the clutch mechanism 2.
[0039] When the automatic shift mode is selected through the change
lever 5a, on the other hand, the automatic shift mode is executed.
In this automatic shift mode, the gear-shift unit 31 and the clutch
control unit 21 are remotely operated on the basis of the various
kinds of information through the automatic transmission remote
operation control unit 41b disposed in the transmission ECU 41, and
the engine 1 is controlled by the engine ECU 42 on the basis of the
various kinds of information.
[0040] Here will be noted the drive system for the gear-shift unit
31 and the clutch control unit 21. As shown in FIG. 1, the
gear-shift unit 31 is provided with a gear-shifting driver circuit
33 for driving the electric motor 32 or the like, and the clutch
control unit 21 is provided with a clutch controlling driver
circuit 23 for driving the electric pump 22 or the like.
[0041] In the control circuit structure of the embodiment, the
gear-shifting driver circuit 33 and the clutch controlling driver
circuit 23 are integrated into an integral driver circuit 34. In
other words, this integral driver circuit 34 has the functions of
the gear-shifting driver circuit 33 and the clutch controlling
driver circuit 23.
[0042] The electric motor 32 of the gear-shift unit 31, the
electric pump 22 of the clutch control unit 21 and so on are
activated when properly fed, through the integral driver circuit 34
(including the gear-shifting driver circuit 33 and the clutch
controlling driver circuit 23), with an electric power from a
battery (or the power source unit) 70 mounted on the vehicle.
Therefore, a harness (e.g., a power feed line or an electric line)
73 is provided between the battery 70 and the integral driver
circuit 34, a harness (e.g., a power feed line or an electric line)
74 is provided between the integral driver circuit 34 and the
gear-shift unit 31 having the electric motor 32 and so on; and a
harness (e.g., a power feed line or an electric line) 75 is
provided between the integral driver circuit 34 and the clutch
control unit 21 having the electric pump 22 and so on.
[0043] On the other hand, the battery 70 is disposed on the chassis
side together with the gear-shift unit 31 having the electric motor
32 and so on and the clutch control unit 21 having the electric
pump 22 and so on, and the integral driver circuit 34 is also
disposed on the chassis side. Therefore, the power feed circuit
including the battery 70, the integral driver circuit 34, the
gear-shift unit 31, and the clutch control unit 21, is disposed as
a whole on the chassis side so that the harnesses 73 to 75 can be
provided via the short routes only on the chassis side. Of course,
the integral driver circuit 34 is arranged near the gear-shift unit
31 and the clutch control unit 21 so that it is arranged spaced
apart from the battery 70.
[0044] On the other hand, the transmission ECU (or the electronic
control unit) 41 is disposed on the cab side where the environments
thereof are better in terms of temperature and vibration than at
the chassis side. Therefore, the integral driver circuit 34 and the
transmission ECU 41 are disposed largely spaced apart from each
other. The integral driver circuit 34 and the transmission ECU 41
are connected through signal lines 81 and 82, and the essential
portion of the gear-shift unit 31 is activated by sending the
command signal from the transmission ECU 41 via the signal line 81.
Likewise, the essential portion of the clutch control unit 21 is
activated by sending the drive signal from the transmission ECU 41
via the signal line 82.
[0045] With this construction, in which the driver circuit 34 is
separated from the ECU 41 and arranged on the side of the clutch
control unit 21 or the battery 70 so that the drive power source is
taken directly from the battery, a malfunction may occur without
any drive signal from the ECU such that the vehicle may exhibit an
unexpected behavior, if any abnormality occurs in the system.
[0046] In this control circuit, therefore, an electrical connection
by the harness 73 provided between the battery 70 and the integral
driver circuit 34 can be interrupted by the ECU 41. In the harness
73, more specifically, a transistor (acting as gear-shifting power
interrupting means and clutch controlling power interrupting means)
91 is incorporated to function as a switch, and signal lines 83 and
84 are connected between the ECU 41 and the transistor 91 and
between the harness 73 and the ECU 41, respectively.
[0047] As a result, the ECU 41 can set the harness 73 in a
conductive state, if a main power signal (interruption signal) is
sent via the signal line 83 to the transistor 91, but can set the
harness 73 in an insulated state if the main power signal is not
sent. Here, the ECU 41 sends the main power signal normally to set
the harness 73 in the conductive state, if the key switch 62 of the
engine is ON, but does not send the main power signal to set the
harness 73 in the insulated state, if the key switch 62 is OFF.
[0048] These setting operations are conducted to prevent the
situation, in which a minute current may flow to the harness (or
the drive signal line) 73 while the engine is being stopped, so
that the electric actuator (including the gear-shift unit 31 and
the clutch control unit 21) may cause a malfunction, and to prevent
the electric power of the battery 70 reliably from being
unnecessarily consumed by such a malfunction.
[0049] Moreover, the ECU 41 has a function (acting as malfunction
determining means) 41c to determine a disorder (or malfunction) of
the power feed circuit such as the harness 73 by monitoring a power
feedback signal from the harness 73 via the signal line 84. If the
electric power is fed from the battery 70 to the integral driver
circuit 34 via the harness 73 although the main power signal is not
sent from the ECU 41, for example, the malfunction determining
means 41c can determine that the electric power is unnecessarily
fed so that the power feed circuit has malfunctioned. If the
electric power is not fed from the battery 70 to the integral
driver circuit 34 via the harness 73 although the main power signal
is sent from the ECU 41, on the contrary, the malfunction
determining means 41c can determine that the power feed circuit has
made a disconnection or an imperfect contact.
[0050] As stated in the foregoing, in preparation for a case in
which the power feed circuit (or the main power feed circuit) such
as the harness 73 fails, a preparatory harness (or a preparatory
power feed circuit) 90 is provided between the battery 70 and the
integral driver circuit 34 and in parallel with the harness 73.
Also in this preparatory harness 90, a transistor (acting as
gear-shifting power interrupting means and clutch controlling power
interrupting means) 92, functioning as a switch, is incorporated,
and a signal line 85 is interposed between the ECU 41 and the
transistor 92.
[0051] The ECU 41, therefore, can set the harness 90 in an
electrically conductive state, if a preparatory power signal
(interruption signal) is sent to the transistor 92 via the signal
line 85, but can set the harness 90 in an insulated state if the
preparatory power signal is not sent.
[0052] Here, the ECU 41 does not send the preparatory power signal
to the transistor 92 to set the harness 90 in the insulated state,
at an ordinary time when the main power feed circuit such as the
harness 73 is normal, so that it can determine that the main power
feed circuit such as the harness 73 has failed. When the engine key
switch 62 is ON, moreover, the ECU 41 interrupts the transmission
of the main power signal to the transistor 91 and sends the
preparatory power signal to the transistor 92 thereby to set the
harness 73 in the insulated state and to set the harness 90 in the
conductive state.
[0053] The control circuit structure of the mechanical-type
automatic transmission according to the first embodiment of the
invention is constructed, as has been described hereinbefore. At an
ordinary time, therefore, the ECU 41 sends the main power signal to
the transistor 91, when the key switch 62 of the engine is turned
ON, to energize the main power feed circuit such as the harness 73
or the like. At this time, the preparatory power signal is not sent
to the transistor 92, but the preparatory power feed circuit such
as the harness 90 interrupts the power feed.
[0054] As a result, the integral driver circuit 34 is activated by
the drive signals from the ECU 41 via the signal lines 81 and 82,
to drive the gear-shift unit 31 and the clutch control unit 21 by
using the electric power fed from the battery 70 through the main
power feed circuit such as the harness 73.
[0055] When the key switch 62 of the engine is turned OFF, on the
other hand, the ECU 41 interrupts the sending of the main power
signal to the transistor 91 thereby to interrupt the power feed of
the main power feed circuit such as the harness 73.
[0056] As a result, it is possible to prevent the situation, in
which the minute current may flow into the harness (or the drive
signal line) 73 when the engine is being stopped, so that the
electric actuator (including the gear-shift unit 31 and the clutch
control unit 21) cause a malfunction, and to prevent the electric
power of the battery 70 reliably from being unnecessarily consumed
by such a malfunction.
[0057] Moreover, the ECU 41 monitors the power feedback signal at
all times from the harness 73 via the signal line 84. The ECU 41
interrupts the transmission of the main power signal to the
transistor 91, when it detects the malfunction of the power feed
circuit such as the harness 73, to set the harness 73 in the OFF
state, and sends the preparatory power signal to the transistor 92,
when the engine key switch 62 is ON, but does not send the
preparatory power signal when the engine key switch 62 is OFF.
[0058] Even if the main power feed circuit such as the harness 73
fails, therefore, the integral driver circuit 34 is enabled by
using the preparatory power feed circuit such as the normal harness
90 or the like to drive the gear-shift unit 31 and the clutch
control unit 21 properly.
[0059] When the key switch 62 of the engine is turned OFF, the
power feed to the preparatory power feed circuit 90 is interrupted
so that the malfunction of the electric actuator (e.g., the
gear-shift unit 31 or the clutch control unit 21) while the engine
is being stopped can be reliably prevented to prevent the
unnecessary consumption of the electric power of the battery 70
reliably.
[0060] Moreover, the gear-shifting driver circuit 33 and the clutch
controlling driver circuit 23 are integrally constructed as the
integral type driver circuit 34 so that the circuit construction
can be made compact.
[0061] Next, a second embodiment of the present invention will be
described with reference to the accompanying drawing.
[0062] FIG. 5 is a diagram showing a control circuit structure of a
mechanical-type automatic transmission according to a second
embodiment of the invention, and the same reference numerals as
those of FIG. 1 designate the similar components.
[0063] In this embodiment, as shown in FIG. 5, the gear-shifting
driver circuit 33 and the clutch controlling driver circuit 23 are
integrated like in the first embodiment as the integral driver
circuit 34. However, this embodiment is different from the first
embodiment in that the integral driver circuit 34 is arranged
integrally with the clutch control unit 21.
[0064] Between the battery 70 and the integral driver circuit 34
and between the integral driver circuit 34 and the gear-shift unit
31, therefore, harnesses (or power feed lines or electric wires) 73
and 76 are provided, respectively. The transistor 91 functioning as
a switch is incorporated in the harness 73 between the battery 70
and the integral driver circuit 34, and the preparatory harness (or
the preparatory power feed circuit) 90 is wired in parallel with
the harness 73. Moreover, the signal line 83 is connected between
the ECU 41 and the transistor 91, the signal line 84 is connected
between the harness 73 and the ECU 41, and the signal line is
connected between the ECU 41 and the transistor 92.
[0065] The control circuit structure for the mechanical-type
automatic transmission according to the second embodiment of the
present invention is constructed as described hereinbefore, so that
it can achieve actions and effects similar to those of the first
embodiment.
[0066] Like in the first embodiment, moreover, the gear-shifting
driver circuit 33 and the clutch controlling driver circuit 23 are
integrally constructed as the integral driver circuit 34 so that
the circuit construction can be made compact.
[0067] When the integral driver circuit 34 is attached directly to
the gear-shift unit 31, moreover, it is seriously affected by the
high temperature or vibration of the engine or transmission so that
the driver circuit 34 has to be strictly protected against the high
temperature or vibration. However, the clutch control unit 21 can
be disposed at a portion such as the chassis or frame where the
temperature or vibration is not relatively severe. Therefore, the
integral driver circuit 34 need not be strictly protected, when
attached directly to the clutch control unit 21, against the high
temperature or vibration so that its durability can be retained at
a low cost.
[0068] Next, a third embodiment of the present invention will be
described with reference to the accompanying drawing.
[0069] FIG. 6 is a diagram showing a control circuit structure of a
mechanical-type automatic transmission according to a third
embodiment of the invention, and the same reference numerals as
those of FIG. 1 and FIG. 5 designate the similar components.
[0070] In this embodiment, as shown in FIG. 6, the gear-shifting
driver circuit 33 and the clutch controlling driver circuit 23 are
made separate. The gear-shifting driver circuit 33 is attached
directly to the gear-shift unit 31, and the clutch controlling
driver circuit 23 is attached directly to the clutch control unit
21.
[0071] Between the battery 70, and the gear-shifting driver circuit
33 and the clutch controlling driver circuit 23, harnesses (or
power feed lines or electric wires) 73, 72a and 72b are provided.
Specifically, the harness 73 is connected at its one end to the
battery 70 and is branched at its other end into the harnesses 72a
and 72b, The harness 72a is connected to the gear-shifting driver
circuit 33 and the harness 72b is connected to the clutch
controlling driver circuit 23.
[0072] The transistor, that functions as a switch, is incorporated
in the harness 73, and the preparatory harness (or the preparatory
power feed circuit) 90 is provided in parallel with the harness 73.
In the harness 90, the transistor 92 is incorporated to function as
a switch. Moreover, the signal line 83 is connected between the ECU
41 and the transistor 91, the signal line 84 is connected between
the harness 73 and the ECU 41, and the signal line 85 is connected
between the ECU 41 and the transistor 92.
[0073] The control circuit structure for the mechanical-type
automatic transmission according to the third embodiment of the
present invention is constructed, as described hereinbefore, so
that it can achieve actions and effects similar to those of the
first and second embodiments.
[0074] Although the present invention has been described in
connection with its embodiments, it should not be limited to those
embodiments and can be modified in various manners without
departing from the gist thereof.
[0075] In each of the individual embodiments, for example, the
transistor 91 is caused to act as the gear-shifting power
interrupting circuit and the clutch controlling power interrupting
circuit. In case the gear-shift unit and the clutch control unit
have different power feed circuit portions as in the third
embodiment, however, each power feed circuit portion may be
provided with the transistor (acting as the gear-shifting power
interrupting means or the clutch controlling power interrupting
means).
[0076] In the structure of the third embodiment, moreover, the
individual driver circuits 33 and 23 need not be attached directly
to the gear-shift unit or the clutch control unit but may be
arranged near the gear-shift unit or the clutch control unit.
[0077] Moreover, the control circuit structure of the invention may
be applied to the gear-shift unit in which the clutch control unit
is constructed without any electric element that demands a large
current and in which an electric element demanding a large current
is used only for the gear-shift unit.
[0078] For the clutch control unit, moreover, an electric actuator
such as an electric motor may be used in place of the clutch
mechanism 2 actuated by regulating the oil pressure, generated by
the electric pump 22, by the control valve 21a.
[0079] Moreover, the control circuit structure of the present
invention may be applied in the various automobiles and not only to
a body construction such as a mono-cock vehicle having a cab on the
chassis, but also to a structure having the body on the
chassis.
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